When vehicles such as, for example, trucks and buses, must pass under or through (as the case may be) unfamiliar overpasses, bridges, tunnels, or the like, it is often very difficult for the driver to gauge whether the clearance height and/or the clearance width is sufficient to accommodate the vehicle. It is particularly difficult when the overpass, bridge, tunnel, etc. is inadequately signed, or when uneven road conditions affect clearance. The problems are particularly severe during night travel.
Accordingly, there is a need for a system and method which provide the vehicle operator with timely warning of insufficient vehicle passage clearance (height and width) and, when necessary, automatically stops the vehicle (e.g., by initiating vehicle braking) if appropriate action is not taken in response to the warning.